1. Field of Invention
The present invention relates to a flexible tube used for an insertion apparatus of an endoscope, etc. and an insertion apparatus including the flexible tube.
2. Description of Related Art
Jpn. Pat. Appln. KOKAI Publication No. 2007-236472, for example, describes an example of combining a plurality of tubes with different bending difficulties (hardness) along a longitudinal axis to form a catheter. This catheter is formed to be continuously more flexible at the distal side in comparison with the proximal side.